Automatic up and down bridge



1933- I. N. CLARK 2,141,030

AUTOMATIC UP AND DOWN BRIDGE Filed July 24, 1937 17 [Sade N Clark INVENTOR Patented Dec. 20, 1938 UNITED STATES PATENT OFFICE 6 Claims.

The invention relates to automatic up and down bridge devices used in connection with superimposed units of blasting torpedoes, and has for its object to provide bridging devices which will engage the walls of the well and support the weight of each individual superimposed torpedo, thereby relieving the crushing strain or efiect of the torpedo on each other, so that when a string of torpedoes are placed in position within the well, they 10 can be accurately placed for blasting the predetermined portion of the well, thereby insuring maximum blasting efficiency.

A further object is to provide the bridging members with outwardly and downwardly inclined and movable wall engaging dogs, moved outwardly into cooperative engagement with the well wall as each torpedo is positioned for supporting a superimposed torpedo.

A further object is to provide each bridge with 0 a socket for receiving the lower end of the next torpedo and guiding the same to a position where it will force outwardly the supporting dogs of the previously positioned bridge so that the previously positioned bridge will, support the last torpedo 25 placed in position.

A further object is to provide the bridges with pivoted upwardly and outwardly movable and inclined dogs, which, upon back pressure, incident to flowing oil in a well, will engage the inner pe- 30 riphery of a Well casing and prevent the torpedo being lowered from floating upwardly with the oil. These dogs also cooperate with the well wall below the casing for preventing upward movement of the bridges after they are once set.

35 A further object is to proidde a well bridge of the character described comprising a cup shaped body adapted to receive the nose of a downwardly moving torpedo, a plate spaced beneath the body and to connect the upper and lower dogs pivotally 40 to the cup and plate, and to provide link connections between the dogs for controlling the movement of the dogs outwardly and inwardly according to whether the plate is moved towards the body when the torpedo suspended therefrom 45 reaches its seat in the previously lowered bridge, or when the weight is suspended from the bridge.

A further object is to construct each bridge whereby, during the lowering operation, the lowered dogs will slidably engage the well casing 50 and prevent outward movement of the upper dogs, thereby preventing sticking of the bridge in the casing during the lowering operation.

A further object is to provide means whereby when a superimposed torpedo is lowered onto the 55 previously positioned bridge, it will engage arms carried by the upper dogs and force said arms outwardly, carrying their link connections between centers, thereby positively anchoring the bridge immediately before the superimposed torpedo is seated, hence placing the weight of the 5 superimposed torpedo on the bridgeinstead of on the previously lowered torpedo.

A further object is to provide the bridge cups with hinged bails. to which a shooters line may be attached for lowering the bridge with a. torpedo l0 suspended therefrom into the well.

A further object is to provide the torpedo nose with an extension member adapted to .pass through the cup shaped body of the previously lowered bridge for engaging the upper pawls and 15 forcing the same outwardly into cooperating engagemcnt with the well wall.

With the above and other objects in view the invention resides in the combination and arrangement of parts as hereinafter set forth, shown in the drawing, described and claimed, it being understood that changes in the precise embodiment of the invention may be made within the scope of what is claimed without departing from the spirit of the invention.

In the drawing:

Figure 1 is a perspective view of one of the. bridge members, showing the same extended and the pawls inwardly positioned as during a lower-i ing operation.

Figure 2 is a vertical transverse sectional view through a portion of a well below the casing and one of the bridge members, showing the position of the pawls when the weight of the next upper torpedo is placed on the bridge and showing in dotted line the position of the parts immediately before the tripping operation and seating of the torpedo.

Figure 3 is a vertical transverse sectional view through the well casing and a bridge member, showing the position of the parts upon upward pressure, for instance if the well flows, thereby V preventing the charge being lowered, from being forced upwardly. s

Figure 4 is a detail side elevation of the lower end of one of the torpedoes, showing a tripping cap thereon, and in section.

Figure 5 is a vertical transverse sectional view 'through a conventional form of ,oil well and well casing, showing torpedoes and bridge members therein.

Referring to the drawing, the numerals I and 2 designate torpedoes of conventional structure used in blasting oil wells, which torpedoes are usually charged with nitroglycerin. These torare used at times, as some blasting operations require as high as a thousand quarts of nitroblast the well, to a sfiflicient'elevationl If the sand is deep, for'instance one hundred feet, the maximum efficiency is obtained if the shot disturbs the whole vertical area. are sufficient in length when superimposed to blast the full area.

a To overcome the above difficulty bridge members with torpedoes suspended therefrom are successively lowered into the well on the hooks 3 of. a shooters line 4. Each bridge member comprises a cup shaped body "member 5 having a conical -chai'nber 6 therein, and adapted to receive the tubular 'trip extensions I of caps 8 carried by the lower ends of the torpedo 2. Hingedlyconnected at 9, between ears III at diametrically opposite sides 'of the body members 5 are the upper gripping dogs II, which dogs extend downwardly and are pivotally connected at I2 to the upper ends of downwardly extending links I3, and arerecei'ved in chambers I I of the links. Links I3 have their lower ends hingedly connected at I5 tothe upper ends of the lower dogs I6, which are in turn hingedly connected at I! to the axially movable bridge plate I8, to the under side of which is suspended, by means of bails I9, the various torpedoes being lowered into the well. Bails I9 are received between ears 2!] and are held in place by means of pins 2 I. When the weight of a torpedo 2 is suspended from the bridge, and on the shooter line hook 3, the parts are in the position shown in Figure 1 with all the dogs housed within the chambers I4 of the links I3. The torpedo and bridge is then lowered through the well casing-22 and the links form guide means for centering the device during the lowering operation. If the well flows during the lowering operation, there is a tendency to float the torpedov being lowered upwardly, and this action will force the bridge plate I8 upwardly and the links I3 will force the upper ends of the lower dogs I6 outwardly from the dotted line positions shown in Figure 3 to the full line position shown in said figure. As the dogs I6 are forced outwardly, their short teeth 23, which incline upwardly and outwardly will engage the inner periphery of the well casing 22 and preven upward movement.

By providing dogs I6, it is obvious that the danger of the torpedo being floated or forced upwardly from the casing onto the well platform is obviated, and at the same time as the fiow stops or the pressure falls, the torpedo and its bridge will continue their downward movement, as the weight of the torpedo will again be suspended from the bridge. v

When the torpedo reaches the bottom of the well as shown in Figure 5, the shooter line hook 3 is detached from the bridge bail 24, and the bail swings to one side by gravity as shown in Figure 2,

and at the same time the weight of the upper structure of the bridge will force pawls or dogs I6 outwardly, however when the next torpedo is lowered the trip extension I passes through the chamber 6 of the cup shaped body member 5 of the previously lowered bridge and engages the a,14 ,oao pedoesare relatively long and a great number The torpedoes inwardly extending arms 25 of the upper dogs II and forces said dogs along with the dogs I6 outwardly through the medium of their link connections I3 until the prongs 23 and 26 engage the inner periphery of the well wall 21 below the casing 22, and in an upwardly and outwardly inclined position and the dogs I II into engagement with the inner periphery 21 of. the well and inclining downwardly. It will be noted that the trip extension I is relatively long and that the dogs will grip the wall for holding the bridge against upward or downward movement before the nose of the torpedo actually seats in the chamber .6, hence the weight 01' the lowered torpedo,will be suppored by dogs II cooperating with the' well wall 21, and will not rest or be imparted to the lowered torpedoes. It will also be seen that dogs IE will prevent the lowered and positioned torpedo from being forced upwardly by flowing liquid.

The above operation continues until the desired number of torpedoes have been positioned for the firing operation, and it is understood that the bridges are left in position during the firing operation and destroyed thereby.

Referring to Figure 3, it will be noted that it will be impossible for the dogs II to move outwardly at any time and cause a jamming of the bridge, as the teeth 23 prevent any further outward movement of dogs l6 and the center pivotal points I2 of the ,links I3 to the dogs can not move outwardly to the outer side of a line drawn between pivotal points 9 and I5, hence the dogs are positively held in the chambers II of the links I3. 7

From the above it will be seen that bridge members are provided for bridging an oil well between torpedoes in a manner where each succeeding torpedo lowered in the well will be supported from the walls thereof rather than by the previously lowered torpedo. It will also "be seen that means is provided whereby there is no danger of torpedoes being floated upwardly by flowing oil in the well, and the device is simple in construction, positive in its operation and may be cheaply manufactured.

The invention having been set forth what is claimed as new and useful is:

1. A bridge member carried by the upper end of a torpedo and adapted to grip a well wall and support from the well wall the next torpedo lowered into the well, said bridge member comprising a chambered body member adapted to receive the nose of a second torpedo above the first mentioned torpedo, a plate below the body member, downwardly extending wall gripping dogs carried by the bodymember, upwardly extendingdogs carried by the plate and adapted to grip the wall in opposed relation to the first mentioned dogs, link connections between said dogs and arms carried by the first mentioned dogs and extending beneath the chambered body member into the path of the nose of the second mentioned torpedo and forming means whereby the second mentioned torpedo will force the downwardly extending gripping dogs outwardly and the upwardly extending dogs outwardly through the medium of the link connections into gripping engagement with the well wall.

'2.- A device'- as setforth in claim 1 including an extension niemberfcarried by the nose of the second mentioned torpedo for tripping the dogs to operative positions before the weight of the torpedo is received on the body member.

3. A device as set forth in claim 1 including a lowering bail carried by the body member and adapted to swing to one side thereof clear of the chamber thereof.

4. A torpedo bridge member of the character described comprising a chamberedbody member, a plate below the bodyQmember, opposed dogs carried by the plate and body member, link connections between the dogs and means carried by the dogs of the body member and adapted to -be engaged by a torpedo nose for forcing all of the dogs into opposed gripping engagement with the well wall before the weight of the torpedo is received on the body member.

5. A torpedo bridge comprising an upper body member, a plate below the body member, means for attaching the upper end of a torpedo to the plate, means for attaching a lowering line to the upper member, downwardly extending well wall gripping dogs pivoted to the upper member, upwardly extending well wall gripping dogs pivoted to the plate, link connections between said downwardly and upwardly extending gripping dogs and forming means whereby upon slack in the lowering line the upper member will force said gripping dogs into gripping engagement with a well wall and in opposed relation whereby upward floating of the torpedo is positively prevented.

6. A device as set forth in claim 5 including means carried by the links for limiting the inward movement of the dogs to a position out of sliding engagement with the walls of the well.

ISAAC N. CLARK. 

